Abrasive toolholder



Sept. 21, 1954 w. J. MILLER ABRASIVE TOOLHOLDER Filed July 17. 1953 Patented Sept. 21 1954 UNITED STATES PATENT OFFICE AERASIVE TooLiioL'nE'R William J. Miller, Philadelphia; Par; assignon to Cooperative Utilities Company, Inc.; Philadelphia; Pa a corporation of Delaware Application July 17-, 1953, Serial No. 368,637

2Glaims. (01. 51-405) The present invention relates to new and use= ful improvements in tool holders and more particularly to holders for abrasive" elements for cleaning and polishing the commutators of auto mobile generators and the like.

The usual method of cleaning and polishing the commutator of a generator or seating the brushes is to hold an abrasive stone against; the commutator while the commutator is rotating. On automobile generators the only access to the commutator without removing the generator from the automobile is through a small inspection opening in the side ofthe generator housing. In many instances the access opening in the generator is relatively small and is only slightly wider than the thickness of a standard long slender abrasive element. Abrasive elements of this type are relatively weak and fragile and accordingly are very difficult to use by themselves for work of this type, since if any breakage occurs, the broken portion of the tool will fall into the generator thereby necessitating disassembly of the genera tor to remove the broken fragment of the abrasive tool.

Witli the foregoing in mind, the principal object of the present invention is to provide a novel abrasive tool holder which will support a stick of abrasive material and is especially adaptable for use in cleaning and polishing the commutators of automobile generators and for seating generator brushes.

A further object of the present invention is to provide a novel abrasive tool which permits the selective interchange and replacement of abrasive elements.

A still further object of the present invention is to provide a novel abrasive tool havingthe features and characteristics set forth which may be manufactured easily and cheaply and is entirely efficient and efiective in operation and use.

These and other objects of the present invention and various features and details of the operation and construction thereof are hereinafter more fully set forth and described with reference to the accompanying drawings, in which:

Fig. l is a perspective view of an abrasive tool holder made in accordance with the present invention;

Fig. 2 is a plan view of the abrasive tool holder illustrated in Fig. 1;

Fig. 3 is a side elevational view of the abrasive tool holder;

Fig. 4 is an enlarged fragmentary longitudinal sectional view taken on line 44, Fig. l, illustrat- 2- ing the means for securing an abrasive stick in the tool holder; and

Fig. 5' is an enlarged transverse sectional view taken on line 5 -5, Fig. 3.

Referring more specifically to the drawings,- reference numeral Hl designates generally atool holder made in accordance with the present in-' vention comprising top and bottom wall members H and I2. respectively, maintained in spaced apart parallel relation by a pair of similar side wall members [3, l3. The top, bottom and side wall members define an opening l4 ex-tending longitudinally of the tool hlde-r H] the full length thereof wh-ich is slightly larger than a stick' of 1, abrasive material adapted to be received in the opening [4. If desired; the top; bottom and side wall members may each be formed or m'olde separately and then cemented together with the side wall members overlying the side edges of the top and bottom wall member, or, alternaltivelyi the entire tool holder may be molded as a unit, for example, as' illustrated in the drawings.

In accordancewith the present invention, means are provided adjacent the forward end of the tool holder HP to selectively engage and grip the abras'ivestick to thereby secure the stick of abrasive material in the tool holder and permit the same to be advanced with respect to the tool holder. To this end, a resilient bearing member l5 formed of spring steel or similar material is secured in the top wall member [I adjacent the forward end of the tool holder and extends downwardly and rearwardly therefrom. Rearwardly adjacent the resilient bearing member I5 is a threaded bushing l6 \which may be inserted in the top wall member H of the tool holder during formation thereof and threadedly receives a knurled and slotted bolt I! which engages the upper surface of the lower extension of the resilient bearing member l5.

After the abrasive tool is inserted into the holder of the present invention, the bolt I7 is threaded downwardly in the bushing 16 against the outer surface of the bearing member l5 and resiliently displaces the bearing member 15 downwardly into engagement with the upper surface of the stick of abrasive material thereby securely gripping the abrasive material and preventing displacement thereof with respect to the tool holder. To advance the abrasive stick .in the tool holder, the bolt I1 is threaded upwardly therein disengaging the bearing member I 5 from the abrasive stick thereby permitting the stick to be moved in the tool holder. By this construction a greater proportion of the abrasive stick may be used than is presently possible since the abrasive stick is gripped immediately adjacent the forward end of the tool holder.

An important feature of the present invention which permits the tool holder to be used effectively when cleaning commutators of generators which have very narrow access openings in the provision of a relatively narrow portion of the tool holder adjacent the forward end thereof. This permits the tool holder to be inserted in an access opening of substantially the same width as the tool holder and then swept back and forth across the face of the commutator during rotation of the commutator to effect a more rapid and more complete grinding and cleaning thereof. To accomplish this the side walls I3, [3 of the tool holder are cut out as indicated at [8, [8 in the drawings, and the side edges of the top and bottom wall members ll and I2 are undercut slightly, for example as shown in Fig. 2, so that the thickness of the tool holder at this point is approximately equal to the thickness of the stick of abrasive material to prevent relative freedom of movement of the tool holder after it is inserted in the generator access opening.

From the foregoing it will be observed that the present invention provides a novel tool holder adapted to support a slender stick of abrasive material and prevent the same from breaking during use of the abrasive material and also permit the abrasive material to be used, for example, for cleaning commutators, seating brushes or grinding high spots off of dies and the like. In addition, it is apparent that the present invention provides a novel tool holder which is of a relatively simplified construction and may be manufactured easily and cheaply.

While a particular embodiment of the present invention has been illustrated and described herein, it is not intended to limit the invention to such a disclosure and changes and modifications may be incorporated and embodied therein within the scope of the following claims.

I claim:

1. In a tool holder for supporting a slender stick of abrasive material, top, bottom and side wall members defining a longitudinal opening in the tool holder to receive the stick of abrasive material, said wall members being cut away to provide a relatively narrow portion rearwardly adjacent the forward end of the tool holder, a resilient bearing member carried by the top wall of the tool holder adjacent the forward end thereof, said bearing member having a portion thereof projecting downwardly and rearwardly of said longitudinal opening, and a member threaded through said top wall rearwardly adjacent said bearing member operable to engage and force the same into engagement with the stick of abrasive material to prevent relative movement of the stick in the tool holder.

2. In a tool holder for supporting a slender stick of abrasive material, top, bottom and side wall members secured together to define a longitudinal opening extending through the tool holder operable to receive the stick of abrasive material, said top, bottom and side walls being cut away to provide a relatively narrow portion rearwardly adjacent the forward end of the tool holder of substantially the same thickness 'as the stick of abrasive material, a resilient bearing member carried by the top wall of the tool holder adjacent the forward end thereof, said bearing member having a portion thereof projecting downwardly and rearwardly of said longitudinal opening, and a member threaded through said top wall rearwardly adjacent said bearing member operable to engage and force the same into engagement with the stick of abrasive material to prevent relative movement of the stick in the tool holder.

References Cited in the file ofthis patent UNITED STATES PATENTS Number Name Date 1,024,126 Fletcher Apr. 23, 1912 2,052,543 Anderson Sept. 1, 1936 2,262,907 Van Assen Nov. 18, 1941 2,377,953 Matton June 12, 1945 2,442,088 Kreutzer May 25, 1948 

